The present invention relates to methods for making food, especially produce, safe for human consumption, while maintaining the palatability of said food, especially where sufficient pure water for rinsing said food is not available, and to compositions, especially in concentrated, or the corresponding diluted liquid form, which are especially suitable for practicing said methods.
Fruits and vegetables, and sometimes other food products such as meats, are desirably washed prior to ingestion in order to remove soils and other unwanted residues which may be undesirably clinging to the surfaces thereof. However, the usual washing process requires a rinse step to effect physical removal of the soil. In many situations, a ready source of pure water is not available for rinsing, even at a low level. It will be appreciated that the formulation of truly effective compositions, especially those which can be used safely by individual consumers, for making fruits and vegetables safe to eat and palatable, when an abundant source of safe water is not available for rinsing, presents a unique problem to the formulator, inasmuch as many art-disclosed cleaning ingredients would, presumably, not be desirable for use in direct contact with foods where they are not completely removed and/or would not provide sufficient antimicrobial action.
Moreover, it would be especially desirable to provide effective, toxicologically-acceptable compositions for food, including fruits and vegetables and/or meats that can be sold in concentrated form and used to create dilute low-sudsing liquid solutions which can be used to effect antimicrobial action and which provide palatable food without removal. Dilute liquid solutions are convenient for the user, since they can be applied directly to soiled fruits and vegetables by simple immersion, thus ensuring that all parts of the food are treated. Clarity of the dilute liquids connotes cleanliness to the user and is thus highly desirable. Low sudsing is an important attribute so that the elimination of any suds is achieved quickly and easily. It is also of advantage if such concentrates can be diluted by the consumer using water that is not safe for use, since that is sometimes the only water that is available.
Unfortunately, many toxicologically-acceptable xe2x80x9ccleaningxe2x80x9d ingredients cannot be used with unsafe, impure water.
The present invention encompasses methods for treating food, including produce, especially fruits and vegetables, (and compositions, as disclosed hereinafter, for practicing said methods) at a basic pH, especially without rinsing, while maintaining palatability. In its broadest aspect, it comprises a method for treating food to reduce the level of microorganisms, said treatment occurring just prior to consumption, comprising the step of contacting the surface of said food with an aqueous treatment composition comprising: optionally, detergent surfactant; and basic buffer to provide a pH of greater than about 10.5 for a period of time in excess of about one half of a minute, the composition being essentially free of any material that adversely affects palatability, wherein said food does not need to be rinsed before consumption.
The present invention comprises several more specific aspects including:
I. A method for making food, including produce and meat, safe to eat comprising contacting the surfaces of said food, shortly before ingestion so as to minimize the chances for recontamination, by direct application of a dilute aqueous treatment composition having a pH above about 10.5, typically comprising:
(a) highly preferably, sufficient to reduce the surface tension and to reduce the viscosity to less than about 50 cp., preferably to less than about 10 cp., and more preferably to less than about 5 cp., to help maximize surface wetting and/or drainage thus minimizing residue, but less than an amount that will affect palatability, preferably less than about 0.5%, more preferably less than about 0.2%, and even more preferably less than about 0.1%, of toxicologically-acceptable detergent surfactant, preferably base-stable anionic surfactant, and more preferably, sodium and/or potassium alkyl sulfate and/or C8-14 soap;
(b) toxicologically-acceptable basic buffer, preferably water soluble potassium and/or sodium and/or calcium hydroxides, ortho-phosphates, carbonates, and/or bicarbonates, to provide a pH of from about 10.5 to about 13, preferably from about 10.9 to about 12.5, more preferably from about 11.3 to about 12.3, but preferably with low reserve alkalinity (xe2x80x9creserve alkalinityxe2x80x9d as used herein is equal to the percent of HCI equivalent needed to lower the pH of the dilute treatment composition to 9.5), that is typically less than about 10, preferably less than about 7, and even more preferably less than about 4, so as to maximize safety, and the level of ortho-phosphate, when present, being from about 0.01% to about 3%, preferably from about 0.05% to about 1%, more preferably from about 0.1% to about 0.5% of ortho-phosphoric acid equivalent;
(c) optionally, from about 0.0005% to about 3%, preferably from about 0.001% to about 1%, and more preferably from about 0.003% to about 0.5%, by weight of calcium ion sequestrant, preferably polyphosphate detergent builder such as the sodium salt of tripolyphosphate (referred to hereinafter as xe2x80x9cSTPPxe2x80x9d) or, a salt of an organic polycarboxylic acid, such as the sodium salt of ethylenediaminetetraacetic acid (referred to hereinafter as xe2x80x9cEDTAxe2x80x9d.) and/or a salt of citric acid to sequester calcium in hard water to control calcium precipitates;
(d) optionally, toxicologically-acceptable preservative;
(e) optionally, toxicologically-acceptable suds suppresser; and
(f) the balance comprising an aqueous carrier selected from water and, optionally, low levels of low molecular weight, toxicologically-acceptable organic solvent such as ethanol, glycerol, etc. and/or minor ingredients; all of the acidic materials above being, of course, neutralized under the alkaline conditions of the product, and said composition being essentially free of any material that is not toxicologically acceptable, said treatment being for a period of time of at least one half minute, preferably at least about 1 minute, and more preferably at least about 5 minutes, followed by draining and/or drying, especially without rinsing, said food being then ready for consumption and having desirable palatability.
The inventions disclosed herein preferably encompass concentrated compositions suitable for use in preparing such dilute compositions for treating food at a basic pH above about 10.5, by diluting with water using from about 0.1% to about 5%, preferably from about 0.5% to about 2%, of the concentrated composition, by weight of the dilute composition, said concentrated composition comprising:
(a) from about 0.1% to about 50% , preferably from about 0.5% to about 20%, and more preferably from about 1% to about 10%, by weight of toxicologically-acceptable detergent surfactant, preferably base-stable anionic surfactant, and more preferably, a C6-16 alkyl sulfate and/or C8-14 soap;
(b) toxicologically-acceptable basic buffer, preferably potassium and/or sodium and/or calcium hydroxide, orthophosphate, carbonate, and/or bicarbonate, to provide a pH of from about 10.5 to about 13, preferably from about 10.9 to about 12.5, more preferably from about 11.3 to about 12.3, in said dilute composition, but with low reserve alkalinity in said dilute composition, preferably less than about 10, more preferably less than about 7 and even more preferably less than about 4, to avoid damage to a human, the level of orthophosphate, when present, being from about 3% to about 60%, preferably from about 5% to about 60%, more preferably from about 10% to about 55%, by weight of ortho-phosphoric acid equivalent;
(c) optionally, from about 0.1 to about 35%, preferably from about 1 to about 25%, more preferably from about 2 to about 20%, of toxicologically-acceptable calcium ion sequestrant, preferably polyphosphate or organic polycarboxylate, more preferably STPP or EDTA, or combinations of the two, to control calcium ions;
(d) optionally, toxicologically-acceptable preservative;
(e) optionally, toxicologically-acceptable suds suppresser; and
(f) the balance comprising compatible, toxicologically-acceptable inert and/or minor ingredients.
In all of the above lists of components, if an ingredient can be classified in more than one place, it will be classified in the first place it can appear. Preferably all ingredients are food grade, since they may be ingested.
A more specific method for preparing food, especially produce such as fruits and vegetables involves exposing the food to a dilute aqueous solution having a basic pH of more than about 10.5, for a period of time of more than about one half of a minute, said aqueous cleaning solution comprising potassium cations and/or sodium cations. These cations are desirable in the diet for many reasons. Therefore, their presence in a composition for use in treating food materials like vegetables and fruits without rinsing is desirable. Also, the potassium cation is more useful than the sodium cation for soaps, since the potassium soaps are quite soluble as compared to the sodium soaps, especially at low temperatures.
An alkaline method for treating food comprises contacting the surfaces of produce with an aqueous solution prepared by creating a solution having a pH of from about 10.5 to about 13, preferably from about 10.9 to about 12.5, more preferably from about 11.3 to about 12.3, using the concentrated composition above and impure water, to provide pure solutions that kill microorganisms on the surface of food. It is important to reduce the level of microorganisms on the surface of food.
Another preferred variation in the above methods for treating food such as produce involves placing concentrated compositions, as disclosed herein, into containers in association with instructions to use the composition to form said dilute solutions to treat food. Such instructions are very important, since the amount of dilution, the time of treatment, the elimination of the need for rinsing, and the ability to use impure water to form the treatment solution are not intuitive. It is also important that the instructions be as simple and clear as possible, so that using pictures and/or icons is desirable.
The balance of the composition can comprise various optional adjunct materials, pH-adjusting agents, perfumes or essences, preservatives, suds suppressors, and the like.
The ingredients in the above concentrated compositions are preferably xe2x80x9cfood gradexe2x80x9d and selected and used in proportions which provide substantially clear dilute compositions. xe2x80x9cSubstantially clearxe2x80x9d includes only minimal haziness, and preferably the compositions are completely clear. The ingredients are also selected to have minimal odor, both initially and after storage. The lack of odor is especially important in compositions for use on food.
In order to mask any objectionable odor, the compositions can contain a food grade or GRAS (defined hereinafter) perfume, or essence, ingredient. Especially preferred for this use are oils derived from citrus fruit, e.g., oranges, lemons, limes, grapefruits, tangerines, tangelos, etc. which contain relatively large amounts of terpenes.
Preferred compositions for use herein contain only materials that are food grade or GRAS, including, of course, direct food additives affirmed as GRAS, to protect against possible misuse by the consumer. Traditionally, most suggestions for cleaning of fruits and/or vegetables have contemplated a commercial scale where there is typically more control over the conditions, especially the amount and thoroughness of rinsing. The present invention includes use by individual consumers without rinsing, so that it is essential that extra safety be built into the product. Failure to rinse thoroughly after cleaning is less of a concern if all of the ingredients are GRAS and/or food grade.
The use and selection of cleaning ingredients for the purpose of washing fruits and vegetables is described by the United States Code of Federal Regulations, Title 21, Section 173.315: xe2x80x9cIngredients for use in washing or lye peeling of fruits and vegetablesxe2x80x9d. These regulations restrict the ingredients that may be used for direct contact with food to those described as xe2x80x9cgenerally regarded as safexe2x80x9d(GRAS), and a few other selected ingredients. These sections also provide certain limitations on the amount of material that can be used in a given context. However, there are no regulations, or suggestions, for methods of making food safe for consumption using aqueous compositions that do not need to be removed. Also, there is no known method for killing microbes using materials like hypochlorite, iodine, etc. at low levels that provide desirable palatability.
All documents cited herein are incorporated herein by reference.